Underbody ventilating structure

ABSTRACT

Underbody ventilating structure includes a ventilation grid sheet having a resilient base portion and a plurality of moldedin body-support projections. A cover sheet is coextensive with the grid sheet and has molded-in recessed portions defining a decorative pattern in the cover sheet such as a woven canesimulating pattern. The body support projections maintain the cover sheet spaced from the base portion of the grid sheet, to form a ventilation space between the grid and cover sheets. The body-support projections are bonded to decorative recessed portions of the cover sheet, to eliminate scrubbing of the cover sheet across the grid sheet. The body-support projections can be rigid, or can be partially collapsible to yield with springlike action for increased comfort.

[ 1 Mar. 27, 1973 United States Patent 1 Trotman 2,810,672 10/1957 Taylor.............................297/D1G.2 3,556,907 1/1971 Nystrand..............................161/127 [54] UNDERBODY VENTILATING STRUCTURE [76] Inventor: Herbert Trotman, c/o Comfort Primary Examiner casmir Nunberg P PE' BOX 1046' Assistant Examiner-Darrell Marquette Virginia Beach, Va. 23541 Altomey shanley & ONe

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A3 "r6 1 nmml M mm 1 FA UIF ing pattern. The body support projections maintain the cover sheet spaced from the base portion of the grid sheet,

[56] References Cited to form a ventilation space between the grid and cover sheets. The body-support projections UNITED STATES PATENTS 1/1966 Williams...............................161/1l0 are bonded to rat v recessed portions of the to eliminate scrubbing of the cover sheet grid sheet. The body-support projections or can be partially collapsible to yield with springlike action for increased comfort.

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a Ma t .n e onu wm a" mom-m flml na ial. MBGTF 534402 653673 999999 111111 9 5259 1 1 870960 0 4852 597248 0556 7 32 33 4 Sheets-Sheet 1 INVENTOR HERBERT H TROTMAN ATTORNEYS Patented March 27, 1973 3,722,955

4 Sheets-Sheet 2 INVENTOR HERBERT H. TROT MAN ATTORNEYS Patented March 27, 1973 3,722,955

4 Sheets-Sheet 3 INVENTOR Patented March 27, 1973 3,722,955

4 Sheets-Sheet 4.

INVENTOR HERBERT H. TROTMAN UNDERBODY VENTILATING STRUCTURE BACKGROUND OF THE INVENTION This invention relates to underbody ventilating structures, and more particularly, to ventilated seat pads for occupants of motor vehicles.

Ventilated pads for seats of automobiles, trucks, and other motor vehicles, conventionally include a fabric cover having an exposed seating surface, and a ventilating support structure which maintains the cover spaced above the motor vehicle seat to form a ventilation space under the body of the seat occupant. The cover fabric is generally foraminous, to allow free passage of air into and out of the ventilation space. The cover must have a decorative appearance because it is exposed to view and must complement the pleasant appearance of most vehicle interior trim. Also, a decorative appearance is most important from the standpoint of saleability.

Ventilated seat pads of the prior art suffer from several disadvantages. Among such disadvantages is the susceptibility of the cover fabric to lateral scrubbing movement across the ventilating support structure when an occupant slides onto the seat or otherwise across the pad. This scrubbing action results in the breakage of the cover fabric, and also in the unsightly spreading of the apertures in the foraminous fabric. Further, prior art ventilated seat pads often are not comfortable, especially for occupancy over extended periods of time.

Accordingly, a main object of the invention is the provision of improved underbody ventilation structures which overcome the disadvantages of the prior art, which eliminate scrubbing of the cover across the ventilating support structure and resultant damage to the cover, which have and retain a pleasing decorative appearance, and which are comfortable for occupancy over extended time periods.

Other objects of the invention will appear from the following detailed description which, in connection with the accompanying drawings, discloses several embodiments of the invention for purposes of illustration only and not for determination of the limits of the invention. For defining the scope of the invention, reference will be made to the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts an underbody ventilating pad embodying principles of the invention.

FIG. 2 is an enlarged view of details of the pad of FIG. 1.

FIG. 3- is an enlarged bottom view of details of the cover sheet of the pad of FIG. 1.

FIG. 4 is an enlarged cross-sectional view on line 4- 4 of FIG. 2.

FIG. 5 is an enlarged view on cross-section line 5-5 of FIG. 2, showing the structure as deformed by the weight ofa seat occupant.

FIG. 6 is a side cross-sectional view, similar to FIG. 4, showing details of another underbody ventilating pad embodying principles of the invention.

FIG. 7 is a side cross-sectional view, similar to FIG. 4, showing details of still another underbody ventilating pad embodying principles of the invention.

FIG. 8 is a plan view of the body-support projections of the structure of FIG. 7.

FIG. 9 is a cross-sectional view showing the action under load of the body-support projections of the structure of FIG. 7.

FIG. 10 is a side cross-sectional view, similar to FIG. 4, showing details of still another underbody ventilating pad embodying principles of the invention.

FIG. 11 is an enlarged, isometric bottom view of details of the structure of FIG. 10.

Primed, double-primed and triple-primed reference characters denote elements similar to elements designated with the respective unprimed characters.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS IN FIG. 1, an underbody ventilating pad 10 has a seat portion 12 and a back rest portion 14. Pad 10 bends along a line of hinging action, as at 15, so that the pad can be folded into a configuration in which seat portion 12 extends transversely to back rest portion 14. In this configuration, pad 10 can be disposed on a motor vehicle seat assembly with the seat portion of the pad resting on the seat portion of the vehicle seat assembly and the back rest portion of the pad resting on the back rest portion of the seat assembly.

Pad 10 includes a first sheet member or ventilating grid sheet 16 (FIG. 2) and an opposed, second sheet member or cover sheet 18, and the two sheets make up the seat and back rest portions of the pad. Grid sheet 16 and cover sheet 18 are unitary sheets of synthetic resinous material (hereafter termed plastic). Each sheet has a uniform thickness, and the cover sheet may be molded into a simulated cane configuration to be described in detail. Grid sheet 16 and cover sheet 18 are coextensive, and the sheets are joined together around their peripheries to form pad 10. The joining can conveniently be effected by sewing the sheets together. If desired, a conventional, narrow edge binding 22 (FIG. 1) can be folded around the edges of and sewn to the sheets, to conceal the raw edges of the plastic or, if desired, the coinciding edges of the sheets can be tear heat sealed together.

Cover sheet 18 has an outer or exposed surface 24 (FIGS. 2, 4) upon which an occupant is seated. Cover sheet 18 also has an inner or concealed surface 26 (FIG. 4) which faces grid-sheet 16. A portion of cover sheet 18 is removed in FIG. 2, for clarity in illustration. It will be appreciated that the structural details shown in FIG. 2 are representative of both the seat portion and the back rest portion of pad 10.

Grid sheet 16 includes a resilient base or web portion 28 (FIGS. 2, 4) and a plurality of body-support projections or portions 30. Body-support projections 30 are molded in the grid sheet and protrude from base portion 28. Base portion 28 interconnects the body-support projections. Body-support projections 30 are hollow, grid sheet 16 being uniform in thickness throughout the body-support projections and base portion 28. Each body-support projection 30 has a generally frustoconical configuration, and has a free inner end portion 32 which is spaced from base portion 28 of grid sheet 16. Each projection 30 includes continuous side walls 34 which merge with a flat end wall 36. The configuration of projection 30 imparts rigidity to side walls 34 from the base portion of grid sheet 16 to end portion 32 of the projection, to prevent collapse of the projection under the weight of a seat occupant. Side walls 34 of each projection have four corrugations, as at 38, which serve to further stiffen side walls 34 against collapse. Body-support projections 30 maintain cover sheet 18 spaced from base portion 28 of grid sheet 16 to form a ventilation space 40 for circulation of air between the cover sheet and the grid sheet.

Body-support projections 30, having generally columnar configurations, are spaced-apart in all directions for free flow of air longitudinally and transversely within ventilation space 40. Base portion 28 of grid sheet 16 has an outer surface 42 facing away from cover sheet 18, for disposition on a motor vehicle seat assembly or other pad-supporting surface. Apertures 44 may be formed in base portion 28 of grid sheet 16,

to minimize crinkling noises produced by deformation of base portion 28 from the weight of a seat occupant. Where present, apertures 44 also promote free flow of ventilating air into and through ventilation space 40. Grid sheet 16 has a flat portion, i.e., a portion free of body-support projections, along line of hinge action (FIG. 1), to facilitate the bending of the pad. The grid sheet also has a flat marginal portional extending around its periphery, to, facilitate the joining of the edges of the grid sheet to the edges of the cover sheet.

The cover sheet is also a single sheet of plastic which bends along the line of hinge action. The cover sheet (FIG. 2) includes a plurality of molded-in recessed portions which define a decorative, woven-cane pattern in the exposed surface of the cover sheet. To define the pattern, the molded recessed portions are shaped and positioned to define a plurality of cane-simulating members and to define intersections of the cane-simulating members and simulated or actual openings in the pattern. At the intersections, the cane-simulating members appear to be in interwoven relation to one another. To illustrate, cover sheet 18 is molded with portions recessed to define a plurality of straight, canesimulating stringers, as at 46. This is effected by displacing material of a flat sheet downwardly along spaced-apart parallel lines, as at 48, .50, leaving a central portion elevated to define the body of stringer 46. By recessing portions of cover sheet 18 to varying depths, the cane-simulating members are made to appear to extend over and under one another in interwoven relationship, intersecting at locations dispersed across cover sheet 18. A typical intersection of eight cane-simulating stringers is indicated at 52. At the intersection, a cluster of additional deeper recessed portions are formed, simulating void spaces occuring between stringers in natural woven cane. The cluster of deep recesses includes a central recessed portion 54 and four peripheral recessed portions 56, 58,60, 62, which are dispersed peripherally around central recessed portion 54. Four of these clusters surround an octagonal recessed portion 63 which simulates an opening in the pattern or the lower end portions of which actually terminate in an opening 68 (FIG. 2). Cover sheet 18 is of uniform thickness throughout the recessed and other portions of the sheet, each recessed portion being molded in the sheet to a depth to have an inner end portion which is spaced from the portions of inner surface 26 (FIG. 4) of cover sheet 18 which are contiguous to the recessed portion. Forexample, recessed portion 54 includes an end portion 64'which is spaced inwardly from inner surface portion 66 which is contiguous to recessed portion 54. Stated differently, each recessed portion appears from the underside of the cover sheet as a protrusion (FIG. 3). Each recessed portion includes continuous side walls and includes an end wall which merges with the side walls at the end portion of the recessed portion. For example, recessed portion 54 (FIG. 4) includes continuous side walls 55 and an end wall 57 which closes the inner end portion 64 of the recessed portion.

The intersections of the cane-simulating members are registered with the end walls of the body-support projections. The central recessed portion 54 of the recessed portions clustered at each intersection is joined to the central portion of end wall 36 of the contiguous body-support projection 30. The joining is preferably effected by a bond between the projection end wall 36 and end portion 64 of recessed portion 54, and the bond is advantageously formed by conventional, thermal-fusion techniques which weld recessed portion 54 to end wall 36. It will be appreciated that other conventional plastic-bonding techniques, e.g., adhesive bonding, can be employed to secure recessed portion 54 to end wall 36.

The joining of each body-support projection 30 to a recessed portion of the cover sheet prevents lateral translational movement of the cover sheet relative to the grid sheet, thereby preventing the cover sheet from scrubbing across and being damaged by the grid sheet during the use of the pad notwithstanding the application of friction and other laterally directed forces to the cover sheet by an occupant sliding onto the seat or otherwise across the pad.

Peripheral recessed portions 56, 58, 60, 62 are displaced outwardly from central recessed portion 54 a distance approximating the distance of side walls 34 of body-support projection 30 from central recessed'portion 54, so that the peripheral recessed portions are offset from projection end wall 36. With this arrangement, portions of the side walls of the peripheral recessed portions facially oppose side walls 34 of the body-support projection when cover sheet 18 is deformed by the weight of a seat occupant resting upon exposed surface 24. As shown in FIG. 5, under the weight of an occupant, flexible cover sheet 18 is forced downwardly toward grid sheet 16, collapsing the side walls of central recessed portion 54. The peripheral recessed portions are lowered into closely spaced, opposed relation to side walls 34 of body-support projection 30, as indicated by the positions of peripheral recessed portions 56, 60 in FIG. 5. It will be appreciated that peripheral recessed portions 58, 62 occupy similar positions,

The opposed relation of the peripheral recessed portions to the projection side walls results in a further resistance to scrubbing of the cover sheet across the grid sheet because lateral forces applied to the flexible cover sheet bring the side walls of the peripheral recessed portions into engagement with the projection side walls, which retard further lateral movement of the cover sheet.

Cover sheet 18 may include the plurality of octagonal ventilation apertures 68 which are'formed in the otherwise continuous, air-impermeable plastic cover sheet at the lower end portion of recessed portions 63. The ventilation apertures may be dispersed over the entire cover sheet, at the bottom of each of recessed portions 63 or they may be scattered over the cover sheet, i.e., at the bottom of some of recessed portions 63 (FIG. 2). Ventilation apertures 68 communicate with the ventilating space between the grid and cover sheets, for free passage of air through cover sheet 18 and into refreshing contact with the body of the seat occupant. Ventilation apertures 68 may be slightly smaller than, and registered with, underlying apertures 44 in base portion 28 of grid sheet 16, for decorative purposes. The slightly smaller size of ventilation aperture 68 in cover sheet 18 also increases the body-support area of the exposed surface of cover sheet 18, for increased seating comfort.

The structure of the embodiment of FIG. 6 is similar to that of FIGS. 1-5, except that the size of each bodysupport projection 30, including end wall 36', is increased relative to the spacing between the peripheral recessed portions of cover' sheet 18', so that the peripheral recessed portions, as 58', 62, overlie at least part of the end'wall. It will be appreciated that only two of the four peripheral recessed portions are shown in FIG. 6. In this construction, the projection end wall is bonded to each of the four peripheral recessed portions, as well as to central recessed portion 54', to resist scrubbing of the cover sheet across grid In the embodiment of FIGS. '7 -9, columnar bodysupport projections 30" are constructed for controlled, force-absorbing collapse. This increases the comfort of the seat occupant while maintaining cover sheet 18" spaced from base portion 28" of grid sheet 16" to avoid blocking ventilating space 40". Each body-support projection 30" includes a plurality of serially disposed, rigid, support portions 68, 70, 72 extending in a direction away from base portion 28" of grid sheet 16". Each support portion has four stiffening corrugations, as at 38" (FIG. 8). The support portions are radially offset one from another so that body-support projection 30" has a stepped configuration. Each support portion is frustoconical in shape. Serially contiguous supportportions are joined by annular, flat, collapsible portions which extend in a direction along base portion 28" of grid sheet 16". For example, collapsible portion 74 (FIGS. 7, 8) is located between serially contiguous support portions 68, 70, and collapsible portion 76 is disposed between serially contiguous support portions 70, 72. Central recessed portion 54" is bonded to end wall 36" of body-support projection 30", for prevention of scrubbing action as described above.

When the weight of an occupant is applied to the seat pad, each body-support projection 30" yields (FIG. 9) with the weight and configuration of the occupants body. Collapsible portions 74, 76 are pressed downwardly out of their original planesof orientation, absorbing the force of the load. However, support portions 68, 70, 72 of the sidewalls of body-support projec tion 30" prevent complete collapse of the projection, to prevent blocking of ventilating space 40". The yielding, springlike action-of of bodysupport projections 30" greatly enhances the'comfort properties of the seat pad.

The structure of the embodiment of FIGS. 10-11 is similar to that 'of FIGS. 1-5, except that the deep recessed portions of cover sheet 18" which are clustered at the intersections have open inner end portions. Stated differently, an aperture or orifice is formed in the cover sheet at the inner end portion of each of the recessed portions. The aperture can be formed by shaving off or otherwise removing the tip of the recessed portion as originally molded in the cover sheet. In this embodiment, the end wall of each of the deep recessed portions is generally annular, and circumscribes the aperture formed in the recessed portion. For example, inner end portion 64 of recessed portion 54" includes a generally annular end wall 57" (FIG. 11) which circumscribes aperture 80 which is formed in the inner end portion of the recessed portion. End wall 57" is bonded to end wall 36" of bodysupport projection 30' in the manner described hereinabove. Obviously, apertures 68 may be formed by shaving off some of recessed portions 63 to leave end walls bondable to body support projections.

The structure of FIGS. 10-11 is particularly advantageous because it more closely simulates woven cane by producing voids between stringers as exist in interwoven natural cane. Further, the apertures in the recessed portions communicate with ventilation space 40" and thus provide additional area for flow of air through the cover sheet, except to the extent that the apertures are blocked by the body-support projections.

In making a ventilated seat pad in accordance with one exemplary application of inventive principles, the grid sheet is produced from a single plastic sheet which is molded into the desired configuration with body-support projections and a base portion interconnecting the projections. The plastic for the grid sheet can be selected from a wide variety of plastics suitable for the purpose. The selected plastic must have sufficient strength and stiffness for the body-support projections to have strength to support the seat occupant without blocking circulation of air through the ventilation space, yet be sufficiently flexible to undulate for seating comfort and have sufficient resiliency to return to its original shape after in-use undulation and distortion. The thickness of the plastic to some extent has an effect upon these factors, and the thickness and the type of plastic selected are correlated to produce a grid sheet having the desired properties. As a specific example, a grid sheet of high-density polyethylene about l5 mils in thickness is suitable. Other suitable materials include polypropylene and vinyl.

Any of a wide variety of plastics is also suitable for the cover sheet. The cover sheet must also be flexible to undulate and distort in use, and is preferably more soft and flexible than the grid sheet to stretch in use and for enhanced seating comfort. The cover sheet also must have sufficient resiliency to recover its original fonn after distortion. As a specific example, a cover sheet of low-density polyethylene about 20 mils in thickness issuitable. Other materials which can be employed include 'copolymers of polypropylene and butyl rubber, and vinyl.

The plastic sheets selected for the grid and cover sheets arepassed through their respective forming operations in which the desired configurations are imparted to the sheets by conventional techniques. The cover sheet is then joined to the tips of the body-support projections of the grid sheet under pressure by conventional, thermal-fusion bonding procedures as described hereinabove. The edges of the pad are joined as previously described.

In use, the seat pad is placed on a motor vehicle seat to be occupied in the usual manner. Irrespective of sliding of the occupant across the seat pad, there will be no scrubbing action of the cover sheet across the grid sheet because any sidewise thrust generated by friction or other forces applied to the cover sheet is effectively resisted by the bonds between the recessed portions of the cover sheet and the body-support projections of the grid sheet. Further, in ventilated seat pads according to the embodiment of FIGS. 1-5, scrubbing is also resisted by the peripheral projections of the intersection clusters abutting the side walls of the body support projections.

It will be appreciated that the highly advantageous results of elimination of scrubbing action and resultant damage to the cover sheet have been achieved by coactively associating decorative recessed portions of the cover sheet with the body-support projections so that the recesses perform the dual functions of defining a decorative pattern in the cover sheet while joining the cover sheet to the grid. It will be further appreciated that these advantageous results have been obtained in combination with the further advantage of increased volume in the ventilation space. Such increased volume is made possible by the raising of the cover sheet which results from supporting the cover sheet by the recessed portions. Additional volume is also created under the elevated portions of the cane-simulating structure.

In ventilated seat pads according to the invention, the grid and cover sheets are integrated, and move together under in-use distortion without blocking air flow, and provide a pad which has long service life because scrubbing and resultant damage are eliminated. The pads are comfortable and decorative in appearance, and remain so through long periods of service.

Pads in accordance with the embodiment of FIGS. 7- 9 combine the foregoing advantages with the further advantage of enhanced comfort resulting from the springlike action of thepartially collapsible body-support projections which yield in accordance with the weight and configuration of the body of the seat occupant.

Openings 44 in grid sheet 16 may be omitted entirely if desired and in such case ventilation is achieved through openings 68 in cover sheet 18 or openings in either or both grid sheet 16 or cover sheet 18 at convenient locations, not shown.

The decorative pattern of the present invention can take many forms in which the cover is embossed or three dimensionally deformed so as to have portions projecting inwardly from the plane of the outwardly facing surface, an example being a simulated woven can pattern. A simulated cane surface is shown and described as a preferred embodiment in this patent application because it is representative of these patterns and incorporates an especially deep deformation of the cover which aids in illustrating the invention.

I claim:

1. Underbody ventilating structure, comprising a first sheet member including a resilient base portion,

a resilient second sheet member opposing the first sheet member,

the second sheet member having an exposed surface defining a decorative pattern which faces away from the first sheet member,

the first sheet member including spaced-apart bodysupport means projecting from the base portion for maintaining the second sheet member spaced from the base portion of the first sheet member to form an underbody ventilation space between the first and second sheet members,

each body-support means having an end portion which is spaced from the base portion of the first sheet member,

the end portion of at least a plurality of the body-support means including an end wall joined to the second sheet member to prevent scrubbing of the second sheet member across the first sheet member, and

means defining ventilation apertures communicating with the ventilation space for flow of air into and out of the ventilation space.

2. The structure of claim 1 in which recessed portions of the exposed surface of the second sheet member form projections on an inner surface facing the first sheet member,

each recessed portion including an end portion spaced from portions of the inner surface which are contiguous to the recessed portion,

the end portion of each of at least the plurality of the body-support means being joined to the end portion of at least one recessed portion of the second sheet member.

3. The structure of claim 2 in which each body-support means has side walls and a generally columnar configuration,

the recessed portions of the second sheet member including a central recessed portion and a plurality of peripheral recessed portions dispersed peripherally around the central recessed portion,

the central recessed portion being joined to the end wall of a body-support means,

the peripheral recessed portions being offset from the end wall to oppose the side walls of the bodysupport means when the second sheet member is' deformed by a body resting on the exposed surface of the second sheet member.

4. The structure of claim 2 in which the recessed portions define a woven-cane pattern with the recessed portions defining intersections of interwoven cane-simulating members at locations registered with end walls of at least the plurality of the body-support means.

5. The structure of claim 3 in which the plurality of recessed portions include a plurality of apertures with at least a portion of such apertures communicating with the ventilation space.

6. The structure of claim 4 in which the recessed portions at each intersection include a central recessed portion and a plurality of peripheral recessed portions dispersed peripherally around the central recessed portion with at least the central recessed portion being joined to the end wall of a body-support means.

7. The structure of claim 2 in which the second sheet member includes at least a plurality of the ventilation apertures,

the ventilation apertures in the second sheet member being interspersed among the recessed portions of the second sheet member.

8. The structure of claim 7 in which the base portion of the first sheet member includes apertures communicating with the ventilation space and registered with the ventilation apertures in the second sheet member.

9. The structure of claim 1 with each body-support means being hollow and having side walls,

the side walls of each body-support means including a plurality of serially disposed support portions extending in a direction away from the base portion of the first sheet member, and

a collapsible portion between serially contiguous support portions.

10. The structure of claim 9 in which the support portions are rigid and radially offset from one another, and t the collapsible portions extend in a direction along the base portion of the first sheet member.

11. The structure of claim 10 with each rigid support portion including at least one stiffening corrugation.

12. The structure of claim 1 in which the first and second sheet members are made of plastic,

the end portion of each of at least the plurality of the body-support means being joined to the second sheet member by a bond between the end portion of the body-support means and the second sheet member.

13. The structure of claim 12 with the end portion of each of at least the plurality of the body-support means being thermal fusion-bonded to the second sheet member.

14. The structure of claim 12 with the end portion of each of at least the plurality of the body-support means being adhesive-bonded to the second sheet member.

15. The structure of claim 12 with the second sheet member being more flexible than the first sheet member.

.16. Underbody ventilating pad structure comprising member,

the second sheet member being of generally uniform thickness material having a surface which is exposed to view and which faces away from the first sheet member,

the second sheet member having an inner surface facing the first sheet member,

the first sheet member including spaced-apart hollow body-support means projecting from the base portion for maintaining the second sheet member spaced from the base portion of the first sheet member to form a ventilation space between the first and second sheet members, the second sheet member including recessed portions defining a decorative pattern in the exposed surface,

each recessed portion including an end portion spaced from portions of the inner surface which are contiguous to the recessed portion,

each body-support means having an end portion which is spaced from the base portion of the first sheet member,

the end portion of at least a plurality of the body-support means being bonded to the end portion of at least one recessed portion of the second sheet member to prevent scrubbing of the second sheet member across the first sheet member,

the second sheet member including a plurality of ventilation apertures communicating with the ventilation space,

the base portion of the first sheet member having a surface facing away from the second sheet member for disposition on a pad-supporting surface.

17. The structure of claim 16 in which the end portion of each of at least the plurality of the body-support means includes an end wall bonded to at least one recessed portion of the second sheet member with the recessed portions defining intersections of interwoven cane-simulating members at locations registered with the end walls of at least the plurality of the body-support means.

18. The structure of claim 16,

each body-support means having side walls,

the side walls of each body-support means including a plurality of serially disposed support portions extending in a direction away from the base portion of the first sheet member, and

a collapsible portion between serially contiguous support portions. 

1. Underbody ventilating structure, comprising a first sheet member including a resilient base portion, a resilient second sheet member opposing the first sheet member, the second sheet member having an exposed surface defining a decorative pattern which faces away from the first sheet member, the first sheet member including spaced-apart body-support means projecting from the base portion for maintaining the second sheet member spaced from the base portion of the first sheet member to form an underbody ventilation space between the first and second sheet members, each body-support means having an end portion which is spaced from the base portion of the first sheet member, the end portion of at least a plurality of the body-support means including an end wall joined to the second sheet member to prevent scrubbing of the second sheet member across the first sheet member, and means defining ventilation apertures communicating with the ventilation space for flow of air into and out of the ventilation space.
 2. The structure of claim 1 in which recessed portions of the exposed surface of the second sheet member form projections on an inner surface facing the first sheet member, each recessed portion including an end portion spaced from portions of the inner surface which are contiguous to the recessed portion, the end portion of each of at least the plurality of the body-support means being joined to the end portion of at least one recessed portion of the second sheet member.
 3. The structure of claim 2 in which each body-support means has side walls and a generally columnar configuration, the recessed portions of the second sheet member including a central recessed portion and a plurality of peripheral recessed portions dispersed peripherally around the central recessed portion, the central recessed portion being joined to the end wall of a body-support means, the peripheral recessed portions being offset from the end wall to oppose the side walls of the body-support means when the second sheet member is deformed by a body resting on the exposed surface of the second sheet member.
 4. The structure of claim 2 in which the recessed portions define a woven-cane pattern with the recessed portions defining intersections of interwoven cane-simulating members at locations registered with end walls of at least the plurality of the body-support means.
 5. The structure of claim 3 in which the plurality of recessed portions include a plurality of apertures with at least a portion of such apertures communicating with the ventilation space.
 6. The structure of claim 4 in which the recessed portions at each intersection include a central recessed portion and a plurality of peripheral recessed portions dispersed peripherally around the central recessed portion with at least the central recessed portion being joined to the end wall of a body-support means.
 7. The structure of claim 2 in which the second sheet member includes at least a plurality of the ventilation apertures, the ventIlation apertures in the second sheet member being interspersed among the recessed portions of the second sheet member.
 8. The structure of claim 7 in which the base portion of the first sheet member includes apertures communicating with the ventilation space and registered with the ventilation apertures in the second sheet member.
 9. The structure of claim 1 with each body-support means being hollow and having side walls, the side walls of each body-support means including a plurality of serially disposed support portions extending in a direction away from the base portion of the first sheet member, and a collapsible portion between serially contiguous support portions.
 10. The structure of claim 9 in which the support portions are rigid and radially offset from one another, and the collapsible portions extend in a direction along the base portion of the first sheet member.
 11. The structure of claim 10 with each rigid support portion including at least one stiffening corrugation.
 12. The structure of claim 1 in which the first and second sheet members are made of plastic, the end portion of each of at least the plurality of the body-support means being joined to the second sheet member by a bond between the end portion of the body-support means and the second sheet member.
 13. The structure of claim 12 with the end portion of each of at least the plurality of the body-support means being thermal fusion-bonded to the second sheet member.
 14. The structure of claim 12 with the end portion of each of at least the plurality of the body-support means being adhesive-bonded to the second sheet member.
 15. The structure of claim 12 with the second sheet member being more flexible than the first sheet member.
 16. Underbody ventilating pad structure comprising a first sheet member of generally uniform thickness material having a periphery and a resilient base portion, and a resilient second sheet member generally coextensive with the first sheet member and having a periphery joined to the periphery of the first sheet member, the second sheet member being of generally uniform thickness material having a surface which is exposed to view and which faces away from the first sheet member, the second sheet member having an inner surface facing the first sheet member, the first sheet member including spaced-apart hollow body-support means projecting from the base portion for maintaining the second sheet member spaced from the base portion of the first sheet member to form a ventilation space between the first and second sheet members, the second sheet member including recessed portions defining a decorative pattern in the exposed surface, each recessed portion including an end portion spaced from portions of the inner surface which are contiguous to the recessed portion, each body-support means having an end portion which is spaced from the base portion of the first sheet member, the end portion of at least a plurality of the body-support means being bonded to the end portion of at least one recessed portion of the second sheet member to prevent scrubbing of the second sheet member across the first sheet member, the second sheet member including a plurality of ventilation apertures communicating with the ventilation space, the base portion of the first sheet member having a surface facing away from the second sheet member for disposition on a pad-supporting surface.
 17. The structure of claim 16 in which the end portion of each of at least the plurality of the body-support means includes an end wall bonded to at least one recessed portion of the second sheet member with the recessed portions defining intersections of interwoven cane-simulating members at locations registered with the end walls of at least the plurality of the body-support means.
 18. The structure of claim 16, each body-support means having side walls, the side walls of each body-support means including a plurality of serially disposed support portions extending in a direction away from the base portion of the first sheet member, and a collapsible portion between serially contiguous support portions. 